[GEEK SCHOOL] Network Security 4: Windows Firewall: Your System’s Best Defense
- by Ciprian Rusen
If you have your computer connected to a network, or directly to your Internet connection, then having a firewall is an absolute necessity. In this lesson we will discuss the Windows Firewall – one of the best security features available in Windows! The Windows Firewall made its debut in Windows XP. Prior to that, Windows system needed to rely on third-party solutions or dedicated hardware to protect them from network-based attacks. Over the years, Microsoft has done a great job with it and it is one of the best firewalls you will ever find for Windows operating systems. Seriously, it is so good that some commercial vendors have decided to piggyback on it! Let’s talk about what you will learn in this lesson. First, you will learn about what the Windows Firewall is, what it does, and how it works. Afterward, you will start to get your hands dirty and edit the list of apps, programs, and features that are allowed to communicate through the Windows Firewall depending on the type of network you are connected to. Moving on from there, you will learn how to add new apps or programs to the list of allowed items and how to remove the apps and programs that you want to block. Last but not least, you will learn how to enable or disable the Windows Firewall, for only one type of networks or for all network connections. By the end of this lesson, you should know enough about the Windows Firewall to use and manage it effectively. What is the Windows Firewall? Windows Firewall is an important security application that’s built into Windows. One of its roles is to block unauthorized access to your computer. The second role is to permit authorized data communications to and from your computer. Windows Firewall does these things with the help of rules and exceptions that are applied both to inbound and outbound traffic. They are applied depending on the type of network you are connected to and the location you have set for it in Windows, when connecting to the network. Based on your choice, the Windows Firewall automatically adjusts the rules and exceptions applied to that network. This makes the Windows Firewall a product that’s silent and easy to use. It bothers you only when it doesn’t have any rules and exceptions for what you are trying to do or what the programs running on your computer are trying to do. If you need a refresher on the concept of network locations, we recommend you to read our How-To Geek School class on Windows Networking. Another benefit of the Windows Firewall is that it is so tightly and nicely integrated into Windows and all its networking features, that some commercial vendors decided to piggyback onto it and use it in their security products. For example, products from companies like Trend Micro or F-Secure no longer provide their proprietary firewall modules but use the Windows Firewall instead. Except for a few wording differences, the Windows Firewall works the same in Windows 7 and Windows 8.x. The only notable difference is that in Windows 8.x you will see the word “app” being used instead of “program”. Where to Find the Windows Firewall By default, the Windows Firewall is turned on and you don’t need to do anything special in order for it work. You will see it displaying some prompts once in a while but they show up so rarely that you might forget that is even working. If you want to access it and configure the way it works, go to the Control Panel, then go to “System and Security” and select “Windows Firewall”. Now you will see the Windows Firewall window where you can get a quick glimpse on whether it is turned on and the type of network you are connected to: private networks or public network. For the network type that you are connected to, you will see additional information like: The state of the Windows Firewall How the Windows Firewall deals with incoming connections The active network When the Windows Firewall will notify you You can easily expand the other section and view the default settings that apply when connecting to networks of that type. If you have installed a third-party security application that also includes a firewall module, chances are that the Windows Firewall has been disabled, in order to avoid performance issues and conflicts between the two security products. If that is the case for your computer or device, you won’t be able to view any information in the Windows Firewall window and you won’t be able to configure the way it works. Instead, you will see a warning that says: “These settings are being managed by vendor application – Application Name”. In the screenshot below you can see an example of how this looks. How to Allow Desktop Applications Through the Windows Firewall Windows Firewall has a very comprehensive set of rules and most Windows programs that you install add their own exceptions to the Windows Firewall so that they receive network and Internet access. This means that you will see prompts from the Windows Firewall on occasion, generally when you install programs that do not add their own exceptions to the Windows Firewall’s list. In a Windows Firewall prompt, you are asked to select the network locations to which you allow access for that program: private networks or public networks. By default, Windows Firewall selects the checkbox that’s appropriate for the network you are currently using. You can decide to allow access for both types of network locations or just to one of them. To apply your setting press “Allow access”. If you want to block network access for that program, press “Cancel” and the program will be set as blocked for both network locations. At this step you should note that only administrators can set exceptions in the Windows Firewall. If you are using a standard account without administrator permissions, the programs that do not comply with the Windows Firewall rules and exceptions are automatically blocked, without any prompts being shown. You should note that in Windows 8.x you will never see any Windows Firewall prompts related to apps from the Windows Store. They are automatically given access to the network and the Internet based on the assumption that you are aware of the permissions they require based on the information displayed by the Windows Store. Windows Firewall rules and exceptions are automatically created for each app that you install from the Windows Store. However, you can easily block access to the network and the Internet for any app, using the instructions in the next section. How to Customize the Rules for Allowed Apps Windows Firewall allows any user with an administrator account to change the list of rules and exceptions applied for apps and desktop programs. In order to do this, first start the Windows Firewall. On the column on the left, click or tap “Allow an app or feature through Windows Firewall” (in Windows 8.x) or “Allow a program or feature through Windows Firewall” (in Windows 7). Now you see the list of apps and programs that are allowed to communicate through the Windows Firewall. At this point, the list is grayed out and you can only view which apps, features, and programs have rules that are enabled in the Windows Firewall.
